Disposable towel

ABSTRACT

This invention relates to a disposable wet towel characterized by an ability to evolve heat immediately prior to use or in use such that the temperature of the towel is increased by as much as 25* or more above ambient when applied to the skin. The evolution of heat is due to the admixture of a reducing agent and an oxidizing agent reactive with said reducing agent which agents are kept separated prior to use of the towel and mixed when the towel is put into use. The agents and products resulting from the reaction thereof are not irritating to the skin. The invention also provides pouches for storing said towels prior to use which pouches contain means for maintaining said oxidizing agent and reducing agent isolated from each other.

United States Patent 1 June 17, 1975 Ravich DISPOSABLE TOWEL [75]Inventor: Leonard E. Ravich, Boston, Mass.

[73] Assignee: Gorham International, lnc.,

Gorham, Maine [22] Filed: Mar. 14, 1973 [21] Appl. No.: 341,277

[52] US. Cl. 206/223; 206/22l; 206/222; 401/] [51] Int. Cl B65d 81/32[58] Field of Search 206/219, 221, 812, 222, 206/223, 205, 209, 210,525; 15/104.93; 128/399 [56] References Cited UNITED STATES PATENTS2,779,465 l/l957 Anderson 206/223 X 3,038,473 6/1962 Ladd 206/222 X3,343,664 9/1967 Poitras 206/219 3,414,927 12/1968 Worcester 206/812 X3,638,786 2/1972 Borecki et al. 206/219 Primary Examiner-Leonard SummerAttorney, Agent, or Firm-Robert L. Goldberg [5 ABSTRACT This inventionrelates to a disposable wet towel characterized by an ability to evolveheat immediately prior to use or in use such that the temperature of thetowel is increased by as much as 25 or more above ambient when appliedto the skin. The evolution of heat is due to the admixture of a reducingagent and an oxidizing agent reactive with said reducing agent 7 whichagents are kept separated prior to use of the towel and mixed when thetowel is put into use. .The agents and products resulting from thereaction thereof are not irritating to the skin. The invention alsoprovides pouches for storing said towels prior to use which pouchescontain means for maintaining said oxidizing agent and reducing agentisolated from each other.

8 Claims, 4 Drawing Figures PATENTEDJUN 17 I975 FIGZ FIGI

FIG?) A W F DISPOSABLE TOWEL BACKGROUND OF THE INVENTION This inventionrelates to wet disposable towels capable of evolving heat upon use toeffect a temperature Wet disposable towels are known in the art.Typically, they are of paper and are stored in an airtight pouch such asan aluminum foil pouch lined with a protective liner such aspolyethylene. When desired for use, the pouch is torn open and the wettowel removed. Such towels are usually impregnated with an aqueoussolution containing various additives such as perfumes, astringents,humectants and frequently menthol to give a cooling effect when appliedto the skin.

SUMMARY OF THE INVENTION The subject invention provides a wet disposabletowel that evolves heat immediately prior to or during use such that itis above ambient temperature when applied to the skin. The evolution ofheat is accomplished by bringing together a reducing agent and anoxidizing agent such that an exothermic chemical reaction results. Theamount of heat evolved and the corresponding temperature rise is in partdetermined by the relative concentrations of the oxidizing agent and thereducing agent. The invention also provides pouches for storing saidtowels prior to use which pouches contain means for maintaining saidoxidizing agent and reducing agent separated from each other.

Accordingly, one object of the present invention is to provide aself-heating, hot disposable towel for application to the skin.

Another object is to provide a towel impregnated with a two part ofaqueous solution, one part of which contains an oxidant and the otherpart of which contains a reducing agent reactive therewith such thatupon mixing of the two parts, there is the evolution of heat.

A further object of the invention is to provide a pouch containing atowel, an aqueous solution of an oxidizing agent and an aqueous solutionof a reducing agent reactive with said oxidizing agent to produce heat,said pouch characterized by means to maintain said oxidizing agent andreducing agent separate from each other.

Other objects and advantages of the invention will be in part apparentfrom the description which follows.

DESCRIPTION OF THE DRAWINGS With reference to the drawings, FIG. 1represents both a front view and a cross-sectional view of a pouchcontaining a towel in accordance with one embodiment of the invention;

FIG. 2 represents a cross-sectional view of a pouch containing a towelin accordance with an alternative embodiment of the invention;

FIG. 3 represents still another cross-sectional view of a pouch inaccordance with a further embodiment of the invention; and

FIG. 4 represents a dispenser for said pouches containing said towels.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The material used for the toweland the pouch containing said towel are in accordance with the materialsof the prior art. Thus, paper is the preferred towel material thoughcloth or a non-woven fabric may be used and a foil such as aluminum foillined with polyethylene, for example, is the preferred pouch material.The pouch must be airtight.

In order to obtain a heat rise immediately prior to or during use of thetowel of the invention. there are brought together two solutions incontact with the towel which undergo an exothermic chemical reaction. Inaccordance with the invention, these materials are an oxidizing agentand a reducing agent, said agents being reactive with each other.

The oxidizing agent may be any one of a wide variety of materialsdepending upon the precise requirement of the particular composition inwhich it is used. Among the oxidants that may be used are hydrogenperoxide, urea hydrogen peroxide, sodium peroxide, sodium perborate,sodium persulfate, ammonium persulfate, potassium persulfate andmixtures of the foregoing.

The quantity of oxidizing agent and reducing agent contained in theliquid composition impregnated into the hot towel will depend in partupon how much heat is desired and in part upon the nature of thebyproducts which may result from the reaction. It is generally desirablethat the amount of reducing agent be at least as great as the amountrequired for stoichiometric reaction with all of the oxidizing agentpresent in the liquid composition. It is generally preferred that 5 to10 mole percent excess of the reducing agent be present in order toinsure complete reaction of all of the oxidizing agent. In some cases,however, the quantity of the oxidizing agent initially present may begreater than the stoichiometric quantity required for reaction with allof the reducing agent because, due to the nature of the reducing agent,it may be desirable to isnure complete utilization thereof. In thesecases, up to 10 mole percent excess oxidant may be employed, saidoxidant being consumed preferably within 15 seconds when used with amixture of a reducing agent, catalyst for the reaction and othermaterials. Both the oxidizing agent and reducing agent, as well as theby-products formed from said reaction, should be harmless to the skin.

The concentration of the oxidizing agent and reducing agent in the totalaqueous composition impregnated into the towel will depend upon theamount of heat required to heat up the composition and towel, and therate at which the heat is dissipated. As little as 0.8 percent by weightof oxidant based upon the total weight of the aqueous compositionimpregnating the towel will suffice when a stoichiometrically equivalentquantity of reducing agent is used. However, at least 1 percent ispreferred and in general, the amount is that amount necessary to heatthe towel at least 25F. above ambient temperature. As the proportion ofthe oxidizing agent and reducing agent is increased, the rate of heatgeneration approaches a maximum which varies depending upon theparticular materials used. Once the maximum rate of heating has beenachieved, further increase in the amount of oxidizing agent and reducingagent has no substantial further effect on the heating rate although thetotal quantity of heat evolved and hence the ultimate temperature towhich the hot towel is heated may still increase. In the case ofhydrogen peroxide or urea hydrogen peroxide, which materials are thepreferred oxidants, it is desirable to avoid concentrations above 10percent by weight.

dant solution during storage.

Because of the special characteristics required of compositions appliedto the skin, there are only a lirnited number of reducing agents whichmay be employed. These characteristics include an ability to react withthe oxidizing agent to provide rapid and adequate heat evolution,stability during normal storage, freedom from objectionable color andodor, freedom from toxicity, from physiological activity, from irritancyand sensitization. As noted above, the amount of heat evolved preferablyis sufficient to raise the temperature of the entire compositionimpregnating the towel by approximately 25F. above ambient temperatureduring a period of 30 seconds, preferably 15 seconds or less aftermixing. Although there exists a substantial number of reductants whichexhibit the first three of the foregoing characteristics, most of themlack to an appreciable extent one or more of the remainingcharacteristicsQThe reductants which have been found to possess all ofthe foregoing characteristics are thiourea and compounds having thestructure in which R, may be hydrogen, lower alkyl, lower hydroxy alkyl,lower alkoxy, or lower alkanoyl, and R may be any of the foregoingexcept hydrogen and may in addition by phenyl. Among such compounds arel-phenyl-2-thiobarbituric acid, l-phenyl-ethyl-2- thiobarbituric acid,l-methyl2-thiobarbituric acid, 1- methyl-S-ethyl-2-thiobarbituric acid,l-methyl-S-ethyl- 2-thiobarituric acid, l-ethyl-5-ethyl-2-thiobarbituricacid, l-phenyl-5-methyl-2-thiobarbituric acid, and the like, all ofwhich are soluble in weakly alkaline aqueous media. The oxidants whichmay be used with the foregoing reductants to produce the desired resultsinclude hydrogen peroxide and urea hydrogen peroxide.

Preferably, the oxidant is present in an amount from 0.8 to about 2percent by weight of the total aqueous composition. The proportions ofoxidant and reductant relative to each other are usually adjusted asdescribed above to insure complete reaction of the oxidant with a smallamount of excess reductant of the order of 5 to percent of the totalquantity of reductant. However in some cases an excess of oxidant may beused, as pointed out above.

The preferred compositions also include a catalyst to accelerate thereaction and hence to accelerate the rise in temperature of thecomposition, although in some cases it is possible to achieve the sameresult by employing an excess of reductant. While a variety of catalystswhich accelerate such oxidation-reduction reactions are well known andmay be used, best results are achieved with such water solubletungstates or molybdates as alkali metal (including ammonium) tungstatesor molybdates, e.g., sodium tungstate, potassium tungstate, sodiummolybdate, ammonium molybdate, etc.,

I which not only accelerate the reaction, but also cause it to follow adifferent course than that followed in the absence of catalyst, at leastin the case when thiourea is the reductant, so that there are notproduced the objectionable end products which are formed in the absenceof catalyst when thiourea is used.

The amount of catalyst required varies with the particular catalystemployed and also with the specific oxidant and reductant present.However, in the case of the preferred tungstate catalyst, the quantityof catalyst for best results is approximately 75 X lO gram atoms oftungsten per mole of reductant, while in the case of molybdatesapproximately 17.5 X l0 gram atoms of molybdenum per mole of thereductant is best. As little as half as much of the catalyst may be usedsuccessfully. Excess catalyst may be used though the additional quantityhas very little effect. Inasmuch as the catalyst promotes decompositionof the oxidant, it should be kept separated therefrom until immediatelybefore mixing of the two parts of the composition. Therefore, thecatalyst is preferably included in that part of the compositioncontaining the reducing agent.

The pH of the composition may be in the range of from 5 to 10. Foroptimum results the pH should be in the range of from 7.5 to 8. In orderto maintain the composition within the desired pH range, it may benecessary to include a buffer in the composition.

While a wide variety of alkaline agents or buffers may be used tocontrol pl-I, such as sodium, potassium or ammonium hydroxide or sodium,potassium, calcium or ammonium carbonate or bicarbonate, best resultsand minimum irritation of the skin are obtained by using a lowerpolyalkanolamine such as diethanolamine, di-isopropanolamine,triethanolamine, or triisopropanolamine. It has been found permissibleto have an excess of one of the preferred polyalkanolamine materialspresent over and above the minimum required to maintain the desired pH,the excess preferably amounting to up to five per cent by weight of thetotal aqueous composition.

In addition to the ingredients noted above and the compositionimpregnated into the towel, other ingredients normally used in themanufacture of wet disposable towels such as astringents, humectants,perfumes and the like may be present in the composition.

As noted above, prior to use, the reducing agent and the oxidizing agentare kept isolated from each other. This is accomplished by use of any ofthe especially designed pouches for the disposable towel illustrated inthe drawings though the drawings should not be considered limiting ofthe various embodiments possible. With reference to FIG. 1 of thedrawings, there is shown a folded paper towel 10 impregnated with asolution of a suitable reducing agent and contained in a waterproof andairtight pouch 11. A pod 12 contains an aqueous solution'of a suitableoxidant along with stabilizers for said oxidant. When ready for use, athread 13 is pulled to rupture pod 12 resulting in release of theoxidant and the admixture of the same with the reducing agentimpregnated in the towel 10. An exothermic reaction is initiated whichwill raise the temperature of the towel about 25F. above ambient. Aftera few seconds, preferably about 10 seconds, the pouch can be ripped openand the towel used.

In FIG. 2 of the drawings, there is represented a variation of the pouchdisclosed in FIG. 1. In this embodi ment, foil pouch 20 lined withpolyethylene is divided into 2 sections 21 and 22 by divider 23. Section21 contains a folded paper towel, a towel of a non-woven fabric or acloth towel 24 impregnated with a solution of a suitable reducing agentalong with perfumes, humectants, stabilizers and other materials asdesired. Towel 25 in compartment 22 is impregnated with a suitableoxidant and stabilizer. The edges 26 and 27 of towel 24 and 25 are soarranged that when pouch 20 is torn such as at location 28, the twotowels can be pulled from the pouch together to provide intimate contactwith each other and initiate the evolution of heat in accordance withthe invention.

FIG. 3 is a third alternative wherein there is provided pouch 30containing a folded towel 31 impregnated with a solution of a reducingagent and any other desired additive. A pod 32 contains an oxidizingagent in a gel form. When the pouch is torn at location 33, the towel 31is passed through the oxidizing gel to initiate the exothermic reactionor, alternatively, the pod is ruptured and the oxidizing gel squeezedonto the towel as described with reference to a dispenser pack shown inFIG. 4 below.

In FIG. 4 of the drawing, there is represented a dis penser pack forboth storing pouches containing the paper towel and for removing thepouches when desired to use the same. The dispenser pack comprises arectangular box 40 having stored therein pouches 41 stacked one upon theother. The dispenser pack is provided with a slot 42 near the bottomthereof which slot is sized to accommodate the removal of the pouch 41.The slot 42 has projections 43 extending downward and into the slot suchthat it constricts the opening. In this way, as the pouch 41 is removedfrom slot 42, the projections 43 make indentations on the pouch whichwill act to rupture a pod (such as the pod of FIG. 3) containing anoxidizing gel and spread the same over the towel so that the twocomponents mix together initiating the exothermic reaction. Theseprojections 43 can be provided by putting a metal strip across the topof the slit, metal being used because of its strength. A serrated edge(not shown) or any other means to rupture the pod within the pouch canbe substituted for projections 43.

The following specific examples are intended to illustrate more fullythe invention, but are not intended to limit its scope.

EXAMPLE 1 A first solution of reducing agent is prepared having thefollowing composition in parts by weight:

Ingredients Parts Thiourea l .52 Sodium tungstatc dihydrate 0.52Triethanolamine 1.00 Perfume 0.39 Water 96.57

The second part consists of an aqueous solution containing 8.2 percenthydrogen peroxide by weight together with the usual amounts of sodiumstannate and EXAMPLE 2 A reducing agent composition was prepared havingingredients as follows:

Ingredients Parts 1-phenyl-5-ethyl-2-thiobarbituric acid 5.00 Ammoniummolybdate tetrahydrate 0.06 Triethanolamine 1.00 Perfume 0.39 DistilledWater 93.55

The oxidizing solution was the same as in Example I. The procedure ofExample 1 was repeated and the rise in temperature of the towel was toabout F.

Similar results are obtained using as the reducing agent a molarequivalent amount of 1-methyl-2- thiobarbituric acid in place ofl-phenyl-S-ethyl-Z- thiobarbituric acid.

EXAMPLE 3 A reducing composition is made having the followingformulation:

Ingredients Parts Triethanolamine l.0 l-phenyl-2thiobarbituric acid 4.8Sodium tungstate dihydrate 0.5 Water 93.7

The second part consisted of an aqueous solution containing 7.9 percenthydrogen peroxide by weight together with the usual amount of sodiumstannate and phenacetin.

Following the procedure of Example 1, upon mixing of the two parts inproportion of 3 parts by weight of the reducing solution to 1 part byweight of the oxidizing solution at room temperature, the towelunderwent a temperature rise of about F.

I claim:

1. An article comprising an airtight pouch where said pouch is dividedinto two chambers, each containing a towel, the towel in one of saidchambers being impregnated with a solution of oxidizing agent and thetowel in the other of said chambers being impregnated with a solution ofreducing agent, whereupon with rupture of said chambers, the two towelsare brought together causing mixing of said oxidizing agent and reducingagent to cause an exothermic reaction and a temperature rise in saidtowels above ambient temperature.

2. The article of claim 1 where said towel is of paper.

3. The article of claim 1 where the concentration of said oxidizingagent and reducing agent in solution is sufficient to provide atemperature rise in said towels of at least 25F.

4. The article of claim 1 where said solution of oxidizing agentcontains a stabilizer.

3,889,804 7 8 5. The article of claim 4 where said oxidizing agentselected from the group of thiourea and a thiobarbituis selected fromthe group of hydrogen peroxide and ric acid urea hydrogen peroxide.

6. The article of claim 4 where said oxidizing agent The article ofmanufacture of (Flam 7 where Sald is a peroxide.

i I 5 reducing agent is thiourea. 7. The article of claim 6 where thereducing agent is

1. AN ARTICLE COMPRISING AN AIRTIGHT POUCH WHERE SAID POUCH IS DIVIDEDINTO TWO CHAMBERS, EACH CONTAINING A TOWEL, THE TOWEL IN ONE OF SAIDCHAMBERS BEING IMPREGNATED WITH A SOLUTION OF OXIDIZING AGENT AND THETOWEL IN THE OTHER OF SAID CHAMBERS BEING IMPREGNATED WITH A SOLUTION OFREDUCING AGENT, WHEREUPON WITH RUPTURE OF SAID CHAMBERS, THE TWO TOWELSARE BROUGHT TOGETHER CAUSING MIXING OF SAID OXIDIZING AGENT AND REDUCINGAGENT TO CAUSE AN EXOTHERMIC REACTION AND A TEMPERATURE RISE IN SAIDTOWELS ABOVE AMBIENT TEMPERATURE.
 2. The article of claim 1 where saidtowel is of paper.
 3. The article of claim 1 where the concentration ofsaid oxidizing agent and reducing agent in solution is sufficient toprovide a temperature rise in said towels of at least 25*F.
 4. Thearticle of claim 1 where said solution of oxidizing agent contains astabilizer.
 5. The article of claim 4 where said oxidizing agent isselected from the group of hydrogen peroxide and urea hydrogen peroxide.6. The article of claim 4 where said oxidizing agent is a peroxide. 7.The article of claim 6 where the reducing agent is selected from thegroup of thiourea and a thiobarbituric acid.
 8. The article ofmanufacture of claim 7 where said reducing agent is thiourea.